Fabrication of a Hierarchical TiO2 Microsphere/Carbon Dots Photocatalyst for Oxygen Evolution and Dye Degradation Under Visible Light.

Anatase hierarchical TiO2 microsphere/carbon dots composite (HTM/CDs) was fabricated by a facile method for active visible light photocatalysis. The phase, morphology, microstructure and optical properties were investigated by X-ray diffraction, scanning electronmicroscopy, transmission electron microscopy and UV-VIS diffuse reflectance spectroscopy respectively. Under visible light illumination, the fabricated HTM/CDs composite was exhibited an enhanced photo catalytic activity compared to that of pure hierarchical TiO2 microspheres (HTM). Such an enhancement in photocatalytic activity can be attributed to an increase in the absorption of visible light. The photocatalytic activity was investigated by the degradation of a model dyemalachite green (MG) and oxygen production through water splitting.We believe that this type of hybrid material could be used as a highly active and stable visible light photocatalyst to remove pollutants as well as energy production with high performance.

Nanostructured Fe3O4@Fe2O3/Carbon Dots Heterojunction for Efficient Photocatalyst Under Visible Light.

A facile method for the synthesis of porous magnetic nanoparticles (Fe3O4@Fe2O3) embedded with carbon dots (CDs) are demonstrated for photocatalysis study. Here, a simple, low-cost and green method is developed to synthesize CDs from natural source. The synthesized carbon dots are highly water soluble and monodisperse with particle size 2­5 nm. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV-Vis absorption spectroscopy, BET surface area were employed to investigate the crystal structure, morphology, surface groups, optical properties, surface area of the synthesized nanocomposites. The photocatalytic performance of the nanocomposites was analyzed for the degradation of methylene blue under visible light and exhibited higher photocatalytic activity compared to Fe2O3 nanoparticles. Here the crucial role of CDs has been illustrated for the enhancement of photocatalytic activity.

Citric Acid Fuctionalized Magnetic Ferrite Nanoparticles for Photocatalytic Degradation of Azo Dye.

In this study different magnetic ferrite nanoparticles (MFe2O4, where M = Fe, Mn, Zn) were synthesized through an aqueous coprecipitation method and then functionalized with citric acid for the degradation of azo dye present in industrial waste water. Here we evaluated the role of citric acid for photocatalytic application. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the catalytic activity in degradation of methyl orange (MO) was evaluated. The rate of MO degradation in different magnetic systems was determined by UV-Vis spectroscopy. The effect of active parameters (pH, initial MO concentration and effect of sunlight) on degradation performance was investigated. For the first time, citric acid chemistry is successfully exploited to develop a photocatalyst that can successfully degrade the dyes. This citric acid functionalized magnetic ferrite nanoparticles are very much effective for photocalytic degradation of dye and also these can be recollected with the help of permanent magnet for successive uses.